Robin Browne steps gingerly down the rocks alongside a highway bridge abutment. The rocks are loose, and littered with broken beer bottles and other glass.

But once safely down, he continues to step carefully. He’s looking for a plant called false mermaid weed — and doesn’t want to step on it as he navigates tangles of thorns to find it.

The weed, which is threatened, is one of about 1,000 plants that are part of the Acadian forest — the eco-region that makes up most of Nova Scotia and parts of New Brunswick, Quebec and five New England states.

Browne is the propagation specialist at Acadia University’s K.C. Irving Environmental Science Centre, where a seed bank program has been growing slowly since 2013. His window for collecting the false mermaid weed seeds in late May and early June was narrow. Because the species is threatened, he needed approval from the Department of Natural Resources, and could only take a small percentage of the seeds, and the seeds don’t last long.

The plant grows along small streams and riverbanks in wooded areas, but its habitat is limited, Browne said. It flowers in May, matures through to mid-June and then dies away as the seeds are dispersed into the ground. During the winter months it germinates before emerging in the spring and repeating the cycle.

“It’s of particular interest to us because it’s an at-risk plant and the seeds do not persist very long in the soil, so we want to make sure we have quantities in our seed bank for the protection of the species.”

Browne says the goal is to preserve and conserve as many species of the Acadian Forest region as possible.

“This area is under-represented in terms of seed banks in general, so we’re focusing on the region as part of our mandate to work on conservation-related issues in this region,” he said.

Herbacious collection

He said the seed bank devotes some efforts to at-risk species, but its goal is to gather all seeds because any species could become endangered at some point, or wiped out.

There is also a seed bank in Fredericton that deals with forest tree and shrub species, so the local one is concentrating almost primarily on herbacious, or non-woody plants.

So far the bank has collected the seeds of about 60 plants. That doesn’t seem like a lot but the window for collecting seeds can be narrow.

Some species are also collected in more than one year. The bank currently has 100 collections in total.

The seed bank was in existence before 2013, but the collections then were more short-term and used for research. It’s only been in the past five years that it has been preserving seeds for the long term and adopting the same procedures and structure of other seed banks around the world.

While 60 species may not seem like a lot to be collected over a few years, Browne says it’s not bad considering the limitations.

“Certainly we’ve been limited by resources in terms of funding and personnel,” he said. “We’d like to be further along in terms of the number of species and the extent of our testing.”

But he said there is more to running the seed bank than collecting seeds. There is documentation and data management that also has to happen to create an operational and functional seed bank program.

Running the seed bank isn’t just a matter of collecting seeds and freezing them, said Alain Belliveau, the collections manager at the Irving Centre. There is also testing and different trials to see how they perform after various periods of being in the bank, and how well they grow comparing various collection areas.

April Muirhead, an intern at the seed bank, said other testing includes seeing what soil types work best for certain plants, so that if something does happen to impact a species, seeds are not used in areas where the ground material or environment makes them less likely to survive.

As that kind of testing is done, further collecting is needed to replenish what has been used while also trying to expand the bank overall.

“You want to have diversity, too,” Muirhead said. “You don’t want to just go to the same sites. You want to collect, ideally, from all across the Acadian Forest, but we’re focusing right now on Nova Scotia and the Annapolis Valley.”

Between 5,000 and 10,000 seeds per species are ideal for a core collection, Browne said. But that’s not always easy because of limitations in populations, time constraints in collecting seeds before they disperse naturally or are picked over by birds, and limits on how many seeds of endangered species can be collected from any one site.

About 20 per cent of the species collected are considered rare or endangered.

Belliveau said there are a dozen species in the Acadian Forest that are listed as species at risk by the federal or provincial governments, but a few hundred are considered to be rare or extremely rare.

“It changes a bit depending on what jurisdiction you’re in,” he said. “Each province has a different set of statuses.”

Something that is flourishing in one part of the Acadian Forest region could be rare in another, he said.

The seed bank itself isn’t a vast, refrigerated cavern of catwalks and vials. Right now it has a humble beginning of a few fridges in different rooms containing jars of seeds. But Browne says he would like to see the day that the bank at the Irving Centre has expanded to the point it has larger rooms full of refrigeration units.